Expression for the force on a particle

1. The problem statement, all variables and given/known data
A particle of mass m is at rest at t=0. Its momentum for t>0 is given by Px=6t^2 kg m/s, where t is in s. Find an expression for Fx(t), the force exerted on the particle as a function of time.

2. Relevant equations

Px=MVx

3. The attempt at a solution

The question seems really simple but momentum confuses me. I know that momentum is related to the area under the Fx(t)curve between Ti and Tf by Pfx-Pix or the change in momentum, but I don't know where to go from there. Something to get me headed in the right direction would be greatly appreciated!

Maybe it is. What level of physics are you taking? Is it calculus-based? It's clear that you already know how to differentiate. If your prof expected you to be familar with calculus and to be aware that F = dp/dt was the true (most general) form of Newton's law, then yes, he has assigned a trivial problem. However, if you prof did not expect you to be familiar with calculus or F = dp/dt, then maybe he thought he had given you a stumper.

By the way, WERE you aware that F = dp/dt before I told you? If not, can you see that F = ma follows from this relation provided the mass of the particle is constant?

Maybe it is. What level of physics are you taking? Is it calculus-based? It's clear that you already know how to differentiate. If your prof expected you to be familar with calculus and to be aware that F = dp/dt was the true (most general) form of Newton's law, then yes, he has assigned a trivial problem. However, if you prof did not expect you to be familiar with calculus or F = dp/dt, then maybe he thought he had given you a stumper.

By the way, WERE you aware that F = dp/dt before I told you? If not, can you see that F = ma follows from this relation provided the mass of the particle is constant?

No. Why would you? They don't ask you for P or Py. They only ask for Px.

I am in calculus physics and I talked to my teacher and he didn't realize that he assigned such an easy problem :rofl:

I was aware that F = dp/dt before you told me but I didn't use it because I thought I was missing something because it seemed too simple of a problem considering it was among the more difficult problems at the end of the chapter.